The quad antenna is an antenna which is frequently used by amateur radio operators. It consists of a driven element and parasitic elements, like a Yagi; however, the elements are square loops.

Advantages over a Yagi-Uda

---> Higher Gain

The 2-element Quad has almost the same gain as a 3-element Yagi-Uda: about 7.5 dB over a dipole. Likewise, a 3-element Quad has more gain than a 3-element Yagi-Uda

---> Radiation Resistance approximately 50Ω

---> Lower Boom Height

---> Shorter Boom

---> Lower Angle Radiation

---> Broader Bandwidth

The bandwidth for a 3-element Quad antenna that is tuned for maximum gain is limited because excursions from the design frequency unbalance the near resonance condition of the parasitic elements. However, by lengthening the reflector and director elements, thus sacrificing approximately 1 dB gain, the entire 10 meter band may be worked with an SWR below 1.75:1.